在python中迭代文本文件的更有效的方式？

with open('filename.txt', 'r') as file:
    for line in file:
        # 处理每一行
        print(line.strip())  # 去掉行尾的换行符

with open('filename.txt', 'r') as file:
    content = file.read()
    # 处理整个文件内容
    print(content)

with open('filename.txt', 'r') as file:
    while True:
        chunk = file.read(1024)  # 每次读取1024字节
        if not chunk:
            break
        # 处理每个数据块
        print(chunk)

with open('filename.txt', 'r') as file:
    line = file.readline()
    while line:
        # 处理每一行
        print(line.strip())
        line = file.readline()

import mmap

with open('filename.txt', 'r') as file:
    with mmap.mmap(file.fileno(), 0, access=mmap.ACCESS_READ) as mmapped_file:
        for line in iter(mmapped_file.readline, b""):
            # 处理每一行，注意这里得到的是字节串
            print(line.decode().strip())